(Adds Nintendo comment, share price, background)
WASHINGTON/TOKYO, Aug 20 (Reuters) - U.S. firm Hillcrest Laboratories has accused Japan's Nintendo Co 7974.OS of infringing four of its patents to make the top-selling Wii game console, filing a complaint with a trade panel, and a lawsuit.
Hillcrest made the filing to the International Trade Commission, which has the power to bar products from the United States if they are made with infringed technology.
The Rockville, Maryland-based company, which has created motion-detecting technology allowing users to select items on a screen by waving a handheld device, also filed a similar lawsuit in the U.S. District Court in Maryland.
"While Hillcrest Labs has a great deal of respect for Nintendo and the Wii, Hillcrest Labs believes that Nintendo is in clear violation of its patents and has taken this action to protect its intellectual property rights," it said in a statement on Wednesday.
A Nintendo spokesman declined comment, saying that documents relating to Hillcrest's petition have not yet been delivered.
The Wii features a motion-sensing controller that lets users direct on-screen play by swinging it like a bat or a tennis racket. The console has been a huge success since its 2006 launch due to its ease of use, innovative game titles and low price.
Shares in Nintendo were down 2.5 percent at 49,150 yen in early afternoon on Thursday, underperforming the benchmark Nikkei average's .N225 0.6 percent slide.
Hillcrest also said other leading consumer electronics companies, not all of whom have been disclosed publicly, had licensed its technology for use in their products. (Reporting by Diane Bartz, Kenneth Li and Kiyoshi Takenaka; Editing by Edwina Gibbs)